Tracking of data associated with a process is often beneficial. For example, data can be collected and analyzed for the purpose of quality control. In a manufacturing environment, the data may consist of measurements of critical product attributes which are sensitive to drift or to unintentional changes of manufacturing parameters. In many processes, the operator has a strong influence on the resultant quality. One example is the spraying of resin during the production of fiberglass reinforced plastics. Another less obvious example is setup for a CNC (computer numerical controlled) machining operation. Even though CNC operations may often be viewed as fully automated, operator controlled setup parameters such as work piece alignment and tool condition affect the quality of the product. For some processes, mistakes can be catastrophic. An example is the chemotherapy intravenous infusion process. If a patient is infused with the wrong drug, a serious reaction or even death could result. It becomes evident that for processes where the operator has a strong influence on the resultant outcome, linking the identity of the operator to process identification or product identification data can be extremely beneficial.
In an industrial setting, associating operator identity with process and product identity allows management to track productivity and quality personnel to determine which individuals make the best product. Once quality personnel know who makes the best product, they can determine what factors are important in making the best product. Plant management can institute a rewards system for the highest productivity or quality. For the chemotherapy infusion process, for example, it might be important to link the patient's name with the drug being infused, the infusion equipment, and the name of the nurse performing the infusion. If liability issues arise in the future, the infusion facility would then have a record establishing their innocence or culpability.
On a larger scale, traceability in the food chain is a problem. Outbreaks of E-coli and salmonella need to be traced to their sources in order to contain the outbreaks. In this case, it is important to generate records linking time information with food identification, distribution, processing, and raw food sources.
In an industrial setting, travelers, i.e. paperwork which travels with the product, are one means to associate operator, process, and part information. In this case, an operator might enter time, date, process, and his initials on a traveler already containing product identification. This process might even be computerized and networked with a terminal at each workstation. The problem here is that if workers associate negative consequences with filling out a traveler, some might conveniently neglect to fill in the paperwork or enter data into the computer. Enforcing compliance with something viewed as either trivial or not in the best interest of the worker is likely to be difficult.
In the setting of a chemotherapy infusion lab, patients are routinely issued identification bracelets. Nurses are taught to identify the patient and the drug before proceeding with infusion. Although meant to assure quality, this procedure does not assure accurate record keeping and almost never associates the infusion device with other infusion data.
Food distribution can be tracked to a certain degree with bills of lading. However, a food processor might receive a single ingredient from multiple sources. In such cases, as public health officials work their way down the food chain, their search broadens instead of narrowing. If the processor were able to determine whose tomatoes went into which bottle of ketchup and who put them there, it would be possible to avoid mass quarantines of produce and the economic hardships that such quarantines impose on growers.